Fluid flow control device



July 13, 1965 R. M. HAVEE 3,194,253

FLUID FLOW CONTROL DEVICE Filed June 21. 1962 X05597 M. HAVEE.

United States Patent 3,194,253 FLUID FLOW CONTROL DEVICE Robert M. Havee, Stamford, Conn., assignor to Pitney- Bowes, Inc., Stamford, Conn., a corporation of Delaware Filed June 21, 1962, Ser. No. 204,206 2 Claims. (Cl. 137-815) This invention relates to a novel fluid flow control arrangement which has no moving parts and which may be utilized to establish and, maintain variable flow paths for a fluid stream. More particularly, the invention relates to a novel fluid flow control system for dividing a fluid supply stream into two constituent streams, one of the constituent streams always flowing through a principal exhaust conduit and-the other constituent stream selectively flowing through one of a plurality of branch exhaust conduits.

Various fluid control devices having no moving parts have recentlybeendeveloped. For example, US. Patents 3,024,805 and 3,030,979 respectively illustrate the jet deflection and induction type arrangements which may be used in controlling a fluid flow. In the operation of such known devices the fluid supply stream passes through a nozzle and is then selectively directed along one of a plu rality of different possible paths by appropriate control means so that for any given operating condition the fluid supply stream remains substantially undivided and extends principally along one predetermined path through the system. The instant invention on the other hand contemplates dividing the fluid supply stream into at least two separate streams which are selectively directed along two of at least three possible flow paths. Here for a given supply stream and a given operating condition of the system two predetermined separate and simultaneous exhaust fluid flow streams are always produced.

One object of the invention is to provide a novel fluid flow control system having no moving parts.

Another object of the invention is to provide a novel fluid flow control system wherein a fluid supp-1y stream is divided into at least two separate streams and one of these separate streams is selectively directed along one of a plurality of different possible flow paths.

Another object of the invention is to provide a novel fluid flow control system wherein a main fluid supply stream is divided into two separate streams, one of the separate streams always flowing along a fixed path while the other separate stream selectively flows along different predetermined paths. I

Further objects and advantages will become apparent as the description proceeds.

In the drawings:

The figure is a plan view in partial axial section and illustrates an elementary embodiment of the instant invention.

Referring to the fig-u-re there is shown a typical construction for an elementary embodiment of the instant fluid flow control system. Here there is provided a main body unit which comprises an elongate-d main tubular member 11 having a straight cylindrical channel or bore 12 formed therethrough. A pair of tubular branch members 13 and .14 respectively formed with straight cylindrical channels or bores 1-5 and 16 are secured as by welding or any other suitable means to an intermediate portion of the main tubular member 11, the bores 15 and 16 respectively communicating with the main bore 12 through apertures 17 and 18 formed in the walls of said member 11. The cross sectional shape and size of the bores 15 and 16 are prefenably substantially the same as that for the bore 12. The divergent branch members 13 and 14 are symmetrically arranged with "ice respect to the main member 11 so that the axes of the bores 15 and 16 are each disposed at substantially the same angle A with respect to the axis 19 of bore 12. The axes of bores 15 and 16 are also substantially coplanar with respect to said axis 19 and intersect the latter at a common point or junction 20. The inner surfaces forming the bores 12, 15 and 16 are smooth and are devoid of any burrs or jagged edges particularly in the region around the jointure of branch members 13 and 14 with the main tubular member 11 and each of the cylindrical bores 12, 15, 16 has a substantially uniform cross sectional size and shape throughout its eflective length. The upstream end 11a of the main tubular member 11 is connected by means of a flexible tube 21 to a fluid flow source indicated by arrow 22.

In the operation of the apparatus of the figure a main fluid supply stream from the flow source is passed through the main bore 12. By flowing through the straight elongated upstream portion of bore 12 the working fluid,

which may be a gas such as air, tends to become 00- lumnated. As the fluid arrives at the junction 20 the main stream divides into two constitutent streams, one constituent stream passing thnough the downstream end 11b of the main tubular member 11 as indicated by arrow 23 while the other constituent stream passes through one or the other of the branch members 13 and 14 .as respectively indicated by the dotted-line flow path indicating arrows 24 and 25. During operation of the device fluid flow will not occur through all of the three tubular members simultaneously, rather flow will occur along only two of the three possible flow paths at any given time. This flow condition will be stable and will persist until caused to change by the application of suitable control pressures as will be more fully described below. There will usually be one initial mode of operation of the flow system that will be preferred when operation of unit 10 is initiated. Here the main columnated fluid stream will divide so that one constituent stream always flows through the downstream end portion 11b of the main tubular member 11 while the other constituent. stream flows through the same preferred branch member 13 or 14. This preference may be attributable to minute diflerences in dimensions and/or positionment of the respective branch members relative to the main tubular member 11.

After initiation of operation the unit 10 may have its operational mode altered or shifted by means of a very simple procedure. Let it be assumed that the above noted initial preferred stable mode of operation of the flow sys tern is such that fluid is exhausting from the unit along the flow paths 23 and 24. By momentarily blocking the flow of fluid along path 24 a fluid flow along path 25 will be established, the flow along path 23 continuing as before. This blocking action may be accomplished for example by simply placing an obstruction over the end of the tubular branch memer 13. Once fluid flow has thus been initiated along path 25 the unit will then be in and will remain in its other stable operational mode wherein fluid flow occurs only along paths 23 and 25. This condition persists even though the blocking of flow along the flow path 24 is terminated. The operating condition of unit 10 may be changed back to the first mentioned mode by simply momentarily blocking the flow path 25 in a manner similar to that just described for blocking flow path 24.

As will be evident the instant fluid flow control device is bistable in operation and has no moving elements; the only movement included being the flow of the working fluid itself. For either operational mode of the device there will be a subatmospheric pressure existing in the nonconducting one of the tubular branch members 13 and 14.

While one embodiment 3,194,253 5- f y 7'; m

of the invention has been shown and described, it'iwill be appa-rent to those skilled in the art that numerous variations andrmodi fications'; may be made pinv the particular. construction with-out departing The-invention claimedis:

1:, A bistable fluid flow control device having no moving;

parts; comprising a main body member having a substan-,'

main fluid conductingfchannel formed? tially cylindrical therethroughg V a a V afpair ofv divergent branchmemberssecuredlto'said main-t body'member', said branchmernbers each hav i ing a channel: for-med t-herethr ough whichcor'nmuni-t cates with said main conducting channelof said main 1 169 i,s,024,s05

1 a body mernber; at a substantially {commons junction point'whereby fluid in flowing through; the upstream 1 portion of said main fiuid' conducting: channel: and i I -;ari1iving at, said junction point eifectively encounters 7 an array'of three' substantially cylindrical exhaust E ca nj zn e f v r paths, namely the 'diveige rltfib'ranchchannels f j and 1 the rdownstr earnfend of said main; channel;

the walls defining eac'h of :the cylindrical ?channe1s}in,; b the region ofgsaidj'junction point-beingssmooth and continuous andhaving a substantially"constant cross'i 1 through said down'st'reafnend of SaidnrainflLiidcBn-J one of: said fbranch channels gent branch. members" are:symmetrically arraligfiqtahd re 1 substantially coplanar; said n ain body? member:

sectional; are-at .wherebyjfluid-sfloyving 1v through; saicl' V main channel is dividedintg w nstituent .iexhaust streams one constituent; st-ream ialw aysi flowing out ducting channeliwhilefthe (other aconstituent istrearng simultaneously selectively rflo'ws outi-thrpugh! only 

1. A BISTABLE FLUID FLOW CONTROL DEVICE HAVING NO MOVING PARTS; COMPRISING A MAIN BODY MEMBER HAVING A SUBSTANTIALLY CYLINDRICAL MAIN FLUID CONDUCTING CHANNEL FORMED THERETHROUGH; A PAIR OF DIVERGENT BRANCH MEMBERS SECURED TO SAID MAIN BODY MEMBERR, SAID BRANCH MEMBERS EACH HAVING A CHANNEL FORMED THERETHROUGH WHICH COMMUNICATES WITH SAID MAIN CONDUCTING CHANNEL OF SAID MAIN BODY MEMBER AT A SUBSTANTIALLY COMMON JUNCTION POINT WHEREBY FLUID IN FLOWING THROUGH THE UPSTREAM PORTION OF SAID MAIN FLUID CONDUCTING CHANNEL AND ARRIVING AT SAID JUNCTION POINT EFFECTIVELY ENCOUNTERS AN ARRAY OF THREE SUBSTANTIALLY CYLINDRICAL EXHAUST PATHS, NAMELY THE TWO DIVERGENT BRANCH CHANNELS AND THE DOWNSTREAM END OF SAID MAIN CHANNEL; 